A class of nonprecious metal derivatives which can catalyze fuel cells and platinum reactions instantly were discovered by Cornell chemists.
This discovery leads us near to the future were hydrogen fuel cells can power cars, generators and spacecrafts which has the least greenhouse gas emissions.
Hector D. Abruna, the Emile M. Chamot Professor in the Department of Chemistry and Chemical Biology in the College of Arts and Sciences, said that cheap metals will help broader distribution of hydrogen fuel cells. Abruna, with co-authors Francis DiSalvo, the John A said that this will lead us far from fossil fuels and closer to renewable sources. Newman emeritus professor of chemistry; Rui Zeng, Yao Yang, Ph.D. '21; Xinran Feng, Ph.D. '21, and Huiqi Li, a visiting graduate student from Xiamen University; and Lauryn M. Gibb '22, published this in the journal Science Advances.
A better future for transportation is not possible if we are depended on combustion engines and fill the air with smog. Hydrogen fuell cells which transform hydrogen directly into electricity and releases only water and minimal amount of heat can be the best alternative for renewable source.
Abruna says that oxygen reduction reaction (ORR) which is an important part of fuel cell is a punishment by God’s to electrochemistry which is anciently sped by platinum and other valuable metals. Platinum which conducts electricity catalyzes many temperamental reactions with aplomb and is certainly not able to survive the extreme acidic conditions of fuel cell but it is costly enough.
Recently, it is been seen that some alkaline metals which are cheaper but were neglected as they can’t withstand acidic conditions have gained importance and can replace platinum soon for fuel cells. A cheaper material which can conduct electricity and catalyze ORR reaction as platinum were to be searched by Abruna and his team.
DiSalvo which is an expert on transition metal nitrides (TMNs) was an obvious choice, said Abruna. TMNs are a class of compounds of cobalt,manganese,iron and other transition metals conducts electricity and when exposed to air forms a thin oxygen based outer shell which is the best surface for catalyzing chemical reactions. The team tested each one's catalyst in hydrogen fuel cell after synthesizing a family of TMNs with conductive nitride cores and reactive oxide shells.
Manganese and iron-based catalyst showed best results but the cobalt nitride catalyst was the best choice among all, said Abruna. It had almost same efficiency as platinum while coasting 475 times less as of Feb. 2.
This can finally make hydrogen fuel cells a reality and if possible, it can replace combustion engines and car batteries with better alternative that just needs hydrogen and never a recharge and just wastes 10% of energy as compared to 75% of a typical car engine.
Abruna said that hydrogen fuel cells are extremely powerful and run at an efficiency which can never be matched by the typical engines. People know that fuel cells are the future but the stability of the cell and the costing of the catalyst are the only concern.
Reference: Rui Zeng et al, Nonprecious transition metal nitrides as efficient oxygen reduction electrocatalysts for alkaline fuel cells, Science Advances (2022).
Journal information: Science Advances
by Tushar Gupta
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